In a bottle treatment machine according to DE 30 29 755 A, the supporting framework of the machine protection device is placed on the machine frame in order to provide external screening of the work stations which are disposed above the machine frame. Height adjustable panes, which consist of a transparent plastics material, are disposed in the areas. Each pane has an upper and lower edge flange which is integral therewith and which faces inwards, and comprises angle sections which extend vertically on the inner faces of the panes and which serve for stiffening, and to which holding devices are fixed. Rollers on the holding devices fit into tracks defined by the vertical pillars. This arrangement represents a conventional design of a machine protection device which is integrated in the installation.
A design for a bottle filling installation is known from the KRONES Magazine, Edition 2/2000, issued by the Executive Board of KRONES AG, D-93068 Neutraubling DE, the assignee of the present invention, at pages 42 to 45, according to which the filling installation is additionally disposed, together with an integrated, completely encapsulated machine protection device, inside a clean room delimited by a supporting frame structure which comprises internal panes and which is fixed between the floor area and the ceiling in the working area. The supporting frame delimits a frame area which does not follow the floor area contour of the installation but which separates the installation from other, free-standing installation regions in the working area, and which is also at a considerable distance from the installation so as to prevent the panes from being contaminated by the installation.
Due to its framed panes, seals, fittings and frame structure, a fully integrated machine protection device tends to exhibit regions of acute contamination which can only be kept clean or cleaned with difficulty. Furthermore, it impedes access, of course, to certain parts of the work stations, and restricts the field of view. If the installation is operated under isolated or clean room conditions, then external screening of the clean room area is required despite the encapsulating machine protection device, which implies a considerable cost of construction.